Description

initscr() is almost always the first routine that should be called (the
exceptions are slk_init(), filter(), ripoffline(), use_env() and, for multiple-terminal applications, newterm().) This determines
the terminal type and initializes all curses data structures. initscr() also causes
the first call to refresh() to clear the screen. If errors occur,
initscr() writes an appropriate error message to standard error and exits; otherwise, a
pointer is returned to stdscr(). If the program needs an indication of
error conditions, newterm() should be used instead of initscr(); initscr() should only
be called once per application.

A program that outputs to more than one terminal should use the
newterm() routine for each terminal instead of initscr(). A program that needs
an indication of error conditions, so it can continue to run in
a line-oriented mode if the terminal cannot support a screen-oriented program, would also
use this routine. The routine newterm() should be called once for
each terminal. It returns a variable of type SCREEN* which should
be saved as a reference to that terminal. The arguments are the type
of the terminal to be used in place of $TERM, a file
pointer for output to the terminal, and another file pointer for input
from the terminal (if type is NULL, $TERM will be used).
The program must also call endwin() for each terminal being used before
exiting from curses. If newterm() is called more than once for the
same terminal, the first terminal referred to must be the last one
for which endwin() is called.

A program should always call endwin() before exiting or escaping from curses
mode temporarily. This routine restores tty modes, moves the cursor to the
lower left-hand corner of the screen and resets the terminal into the
proper non-visual mode. Calling refresh() or doupdate() after a temporary escape causes
the program to resume visual mode.

The isendwin() routine returns TRUE if endwin() has been called without any
subsequent calls to wrefresh(), and FALSE otherwise.

The set_term() routine is used to switch between different terminals. The screen
reference new becomes the new current terminal. The previous terminal is returned
by the routine. This is the only routine which manipulates SCREEN pointers;
all other routines affect only the current terminal.

The delscreen() routine frees storage associated with the SCREEN data structure.
The endwin() routine does not do this, so delscreen() should be called
after endwin() if a particular SCREEN is no longer needed.

Return Values

endwin() returns the integer ERR upon failure and OK upon successful completion.